Modeling Mesoscale Eddies: the Effects of Resolution onOcean Turbulence

Abstract

We describe a non-adiabatic idealized model for studying mesoscale turbulence in the global ocean. Using the ocean model Oceananigans, we perform a grid refinement study to determine the minimal resolution required to represent mesoscale eddies in the primitive equations. Convergence is evaluated through several metrics, including surface and depth-integrated kinetic energy, spectra, and zonally-averaged temperature, in order to establish quantitative resolution thresholds for physical fidelity. We find that while coarse-resolution simulations capture large-scale flow features, key mesoscale dynamics—including vertical stratification gradients and kinetic energy spectra—only converge at resolutions finer than 1/4°. Differences between the 1/8° and 1/16° simulations are small, suggesting that 1/8° resolution may be sufficient for resolving the mesoscale eddy field for many diagnostic purposes in idealized setups.